P24 Test Question

[fighting2013foever]

Dear experts, I am an Asian woman. I had unprotected sexual intercourse with a man, who I unknow his hiv status. 30days later(yesterday), I went to have a hiv test, the test was duo test(hiv1,hiv2 and p24), the result was negative.
1, Some say that p24 can only test hiv1(not hiv2 and other subtypes),is it true?
2, If p24 only test hiv1 before antibody appears, hiv2 and other subtypes can’t be detected , is the negative result conclusive to me? Do I need test again?

[Edward W Hook, MD]

Your question is repetitive.  As I said before " whether perfromed as part of a DUO test or by themselves provide consclusive results at 8 weeks following exposure."  

There will be no further answers.  EWH

[fighting2013foever]

This is the last question. Please answer me only to the question not considering my risk level .  If someone infect hiv2 and other subtypes, is the duo test 30days after exposure  conclusive? thank you very much.

[Edward W Hook, MD]

Your question is a bit hard to follow however, antibody tests, whether perfromed as part of a DUO test or by themselves provide consclusive results at 8 weeks following exposure.

As I said, you really have virtually nothing to worry about. EWH

[fighting2013foever]

3.How long may the window period be ,only considering antibody test in duo test with 4th generation test？

[fighting2013foever]

thank you so much.

[fighting2013foever]

1.Is the duo test result after 4 weeks after exposure conclusive for me as you said to others before?
2.Excepting for p24 test, only considering antibody test in duo test, is antibody test in duo test with 4th generation more sentive than 3rd generation test？And is the window period shorter than 3rd generation test？

[Edward W Hook, MD]

Welcome to the Forum. I'll try to help.  As i work through your questions however, please remember that your risk of infection, even before testing was very low.  Most heterosexual men do not have HIV and only 1 in 1000 unprotected sexual exposures lead to infection.  thus, even before you were tested, your risk for HIV was very, very low- statistically between 1 in 100,000 and 1 in a million.  Your test results make your risk for infection even lower.

Now for your questions:
1, Some say that p24 can only test hiv1(not hiv2 and other subtypes),is it true?
Yes, I believe this is correct. The p24 antigen test is designed to detect HIV-1 infection.

2, If p24 only test hiv1 before antibody appears, hiv2 and other subtypes can’t be detected , is the negative result conclusive to me? Do I need test again?
Remember, though the p24 targets HIV-1, your antibody tests which would detect HIV-1 or HIV-2 would get well over 90% of infections with all HIV viruses, Thus, your negative result is strong evidence that you are not infected and, when considered with the facts I provided above, makes your risk for infection substantially less than 1 in a million.  This is not something you should worry about.

3, If someone infect hiv2 and other subtypes, is the duo test 30days later conclusive? .
This is essentially the same as your question number 2. See above.

4, During hiv window period,  before hiv1antibody and hiv2 antibody appear ,
If p24 can only test hiv1, it means that hiv2 can't be detected this time, am I right?
    Upon described above, someone infect hiv2 and other subtypes, is the duo test after 4 weeks after exposure conclusive?

This is a "what if" question involving a very rare situation which I have never encountered or heard of.  It should not concern you unless you worry every day that you will be hit by lightning because you are much more likely to be hit by lightning than for this to happen.  I urge you not to worry.  I would not worry and would not test further.  Repeat tests will almost certainly be negative as were your tests yesterday.  EWH

[fighting2013foever]

4, During hiv window period,  before hiv1antibody and hiv2 antibody appear ,
If p24 can only test hiv1, it means that hiv2 can't be detected this time, am I right?
    Upon described above, someone infect hiv2 and other subtypes, is the duo test after 4 weeks after exposure conclusive?
    Forgive my poor English......

[fighting2013foever]

3, If someone infect hiv2 and other subtypes, is the duo test 30days later conclusive?